I ran all my wires under the seat since I moved the fuel tank. Theres lots of room under there and it was pretty easy to get to. I ran all the outside wires out under the cab and the inside wires up under the dash by the left kick panel and under the carpet. I had a lot of wires from the dash area because I ran everything to and from the dash back to the same point under the seat. Nothing thru the firewall. I used a lot of relays to keep the heavy current out of the dash. Joe